1. Field of the Invention
This invention relates to weapon systems employing a liquid propellant, and particularly to such systems wherein the propellant is continuously pumped into the combustion chamber as the projectile advances along the firing bore.
2. Prior Art
Weapon systems providing traveling charge effects on projectiles, or rockets, or other systems are listed in my earlier patent U.S. Pat. No. 4,069,739 issued on Jan. 24, 1978. In that patent I disclose a recoilless gun having a cased, preloaded cartridge. The cartridge has a burstable diaphragm and an annular piston for continuously pumping liquid into the combustion chamber as the projectile advances along the firing bore. Such weapon systems are also listed in U.S. Pat. No. 4,043,248, issued to M. J. Bulman et al on Aug. 23, 1977. In that patent Bulman et al disclose an annular piston for continuously pumping liquid into a forward combustion chamber and into an aft combustion chamber as the projectile advances along the firing bore.
In most of the prior art liquid propellant guns, a relief valve is required to prevent the flow of liquid propellant through the injection orifices during the filling operation. Conventional spring loaded poppets can be utilized, but achieving a large liquid flow area requires a large number of poppets. Design complexities arise and structural integrity is difficult to maintain.
The use of nested rings in heart valves or compressor valves is shown in U.S. Pat. Nos. 3,134,399, issued to A. Deminger et al on May 26, 1964; 3,378,029, issued to D. E. Lee on Apr. 16, 1968; 3,536,094, issued to F. E. Manley, Jr. on Oct. 27, 1970; 3,898,999, issued to J. D. Haller on Aug. 12, 1975; and 3,999,898, issued to W. Chomczyk et al on Dec. 28, 1976.
An object of this invention is to provide an improved liquid propellant gun having an annular piston whose head is also a massive relief valve for providing a relatively high rate of flow therethrough.
A feature of this invention is the provision of a liquid propellant gun having an annular piston whose head is formed of nested rings to provide a relatively high rate of flow from the aft face of the head to the forward face of the head.